1. Field of the Invention
The present invention relates to a trunnion cross used for connecting two yokes via four trunnions which are arranged in two pairs on the trunnion cross. The trunnions of each pair of the trunnions are located diametrically opposite each other and each pair of the trunnions defines an axis, wherein the two axes of the trunnions extend perpendicularly to each other. Each yoke defines a pair of eyes receiving a roller bearing each. The trunnions are adapted for mounting in the roller bearings. The trunnion cross defines two throughbores extending in the direction of the two axes. Throttle inserts are inserted in the throughbores for pressure reduction.
2. Description of the Prior Art
German Offenlegungsschrift 27 21 706 discloses a trunnion cross in which, for improving the lubricant distribution, inserts are inserted into the bores provided for the lubricant which inserts effect a pressure reduction of the lubricant. The throttle device provided in accordance with this prior art reference is a disk which defines a bore having a very small diameter of approximately 0.8 mm.
A throttle bore of such a small size is necessary because of the small axial length of the throttle member provided in the above-mentioned German reference. The small diameter of the throttle bore has the disadvantage that it is easily clogged by dirt particles which may be present in the lubricant. For this reason, a separate filter disk is provided by means of which any dirt particles are retained, so that they do not reach the throttle disk. In the prior art reference, the throttle disk is called a baffle plate or stop disk.
The throttle device according to the prior art reference has the particular disadvantage that over the long term it is possible that the bores of the filter disk will also be clogged. In addition, the entire throttle device is very complicated. Also, since the throttle device requires a substantial amount of space, it can hardly be used in small trunnion crosses.
It is, therefore, the primary object of the present invention to provide a throttle device in a trunnion cross which ensures a uniform reduction of the lubricant pressure toward all four trunnion bearings, while avoiding the danger of clogging of a through passage by dirt particles. In addition, it should be possible to eject any plugs which are formed by hardening lubricant and which may cause clogging of a lubricant passage.